Tandem axle assembly



July 20, 1948. w. c. NABORS 2,445,686

TANDEM AXLE ASSEMBLY Filed April 6, 1946 s Sheets-Sheet 1 Q. 0 Q o '0 mO s o 2 o t II 'I I 2 I Xx I N I: all Illu- K v 5 v \v g\ 2 \l N to 0 0o OLJ b O o o O y 1948- w. c. NABORS 2,445,686

TANDEM AXLE ASSEMBLY Filed April 6, 1946 5 Sheets-Sheet 2 July 20, 1948.w. c. NABORS TANDEM AXLE ASSEMBLY -3 Sheets-Sheet 3 Filed April 6, 1946YUM) c.

Patented July 20, 1948 UNIT EiD' This invention relates-to a tandem-axleas sembly.

It is anobject of the invention to'provide'an axle assembly for fourwheeled trailersofsuch construction that the front and rear-wheels-will'be kept in alignment with the direction of travel j even though theturning-radius will be absorbed by the tires or slippage.

Another object of the invention is to provide an assembly of thecharacter described which, while' retaining directional alignment of thewheels will allow each axle, com lete. freedom .of movement to permitthe tires to follow the contour of the ground surface at all times.

It is a further object of the presentinventioni to provide. an assemblyof theicharacter described wherein the wheels may move verticallyindependent of each other. hicle to move over unevenlsurfaces withoutsubjecting the assembly to undue stress while at the same timemaintainingthe front and rear wheels in alignment with the direction oftravel.

Other objects and advantages will be apparent from the followingspecification which is illustrated by the accompanying drawings wherein-Figure 1 is a bottom plan view of the axle assembly.

Figure 2 is a longitudinal, sectional view taken on the line 2-2 ofFigure 1.

Figure 3 is a cross-sectional view taken on the line 3-3 of Figure 1.

Figure 4 is a fragmentary, longitudinal, sectional view taken on theline 44 of Figure l; and

Figure 5 is a side elevation of the assembly as 5 applied in use.

Referring now more particularly to the drawings wherein like numerals ofreference designate the same parts in each of the figures, the

numerals I and 2 designate the rear and front axles, respectively, of atrailer on whose spindles the rear wheels 3, 3 and front wheels 4, 4 aremounted to rotate.

The numeral 5 designates a trailer body of any selected design. In thepresent illustration there are the side brackets 6, 6 depending from thetrailer body and to the lower ends of which the transverse master axle lis welded or otherwise secured.

These axles I, 2 and I are formed of metal bars 5 are mounted on thesaddles 9, 9 and the leaves This allows the -veof the respectiveassembles are clamped in assenrbled relation bymeans of-theinverted=-U-- bolts ll; "I ll whichsurround the respectivespringassemblies and whosefree "ends extend through the saddle flangesand are securedthereto bythe nuts H. The saddles 9 are formed withtransversely aligned-"bearings!Z and the ends of the master axlel areformed with spindles about which the saddles may turn.

The-.ends of the spring assemblies aresupported on-the front and rearspring perches,- as l i3 ands; 1.4 whic-hdaresuitably-secured to the"front andirearaxlesd and 2:

Accordingly the body 5 and- 'th'e' master axle. 1' will be yielding-1ysupported on t-he -front and rear' axles "and 2 Tby the side :spr'ingassembliesfl'id and .as .tthe fronteandrear wheels =-i3 rand 4, on

either side; assume: different elevations due "to irregdlaritieswof theeground surf-acethe corre sponding spring assembly may rotate about i themaster axle;- and in ithis connection it 1 is to he:

noted that the spring assembly on one side may rotate about the masteraxle independently of the rotation of the spring assembly on the otherside. However, irrespective of the vertical movements of the wheelsrelative to each other the distribution of the load on each of the fourwheels will be maintained substantially uniform.

Secured to the master axle 1, underneath, and spaced apart are thebrackets l5, [5. These brackets are preferably welded to the masteraxle 1. Between said brackets are the oblong, rear and front blocks l6,H which are provided with end pintles l8, l8 and I9, l9 which rotate insuitable bearings in the brackets l5. Accordingly the blocks I6, I!rotate on axes which are transverse with relation to the assembly.

Fitted against the rear and front sides, respectively, of the block I6,I! are the rear and front yokes 20, 2|. There are the rear and frontpivot pins 22, 23 which are fitted centrally through the block I6, I! aswell as through central bearings in the yokes 20, 2|, They have innerend heads which engage the inner sides of the corresponding blocks andhave retaining nuts 24, 25 screwed onto their outer ends whereby theyokes are mounted to pivot, or rotate, on longitudinal axes.

There are the rear and front radius rods or bars 26, 26 and 21, 21. Theouter ends of these bars are bolted in the spring perch assemblies l3,l3 and l4, M, respectively, and they conver e inwardly and their innerends are secured, preferably by welding, to the respective yokes 20, 2|.

Assuming that the wheels 3 and 4 are traveling over comparatively smoothroads upon downward movement of the body relative to the axle assembliesthe spring will move toward a straight line position, the master axle 1moving downwardly and the rear and front radius rod assemblies 26, 21will also move downwardly pivoting about the axes of the pintles l8, l9.In passing over uneven road surfaces either the rear or front wheels maydrop down into a depression whereupon the corresponding radius rods willpivot about the corresponding pintles l8, or l9, as the case may be; or,on the other hand one front, or rear, wheel may drop into a depression,or may strike an elevation, whereupon the corresponding radius rodassembly 26, or 21, as the case may be may, pivot about thecorresponding pivot pin 22 or 23 ona longitudinal axis. It is,therefore, apparent that the wheels may follow uneven surfaces but theload will be distributed onto the respective wheels irrespective of thevarious positions the axle assembly may assume. At the same time thewheels will be maintained in alignment with the direction of travelirrespective of their elevation with respect to each other.

The drawings and description are illustrative merely while the broadprinciple of the invention will be defined by the appended claims.

What I claim is: 1

1. An assembly of the character described comprising, front and rearaxles, ground wheels supporting the axles, spring perches secured to thefront and rear axles and spaced apart, a load supporting master axlebetween, and substantially parallel with, saidfront and rear axles, sidespring assemblies which are spaced apart and whose front and rear ends,respectively, rest on the corresponding spring perches, spring saddleshaving bearings to receive end spindles of the master axle, means forclamping said spring assemblies to the respective saddles, front andrear brackets secured to and depending from the master axle, blocksmounted to rotate on transverse axes between the front and rearbrackets,

front and rear yokes mounted to pivot on longi- 5 tudinal axes on therespective blocks, front and rear radius bars fixed to the respectivefront and rear yokes and diverging therefrom and whose outer ends areimmovably secured to the corresponding front and rear axles.

2. An assembly of the character described comprising, front and rearaxles, spring perches secured to the front and rear axles and spacedapart, a load supportin master axle between, and substantially parallelwith, said front and rear axles, sidespring assemblies which are spaced7 apart and whose front and rear ends, respectively, rest on thecorresponding spring perches,

spring saddles having bearings to receive end spindles of the masteraxle, means for clamping said spring assemblies to the respectivesaddles, front and rear brackets secured to and depending from themaster axle, blocks mounted to rotate on transverse axes between thefront and rear brackets, front and rear yokes mounted to pivot onlongitudinal axes on the respective blocks, front and rear radius barsfixed to the respective front and rear yokes and diverging therefrom andwhose outer ends are immovably secured to the corresponding front andrear axles.

WILLIAM C. NABORS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,108,323 Weiss Feb. 15, 19382,239,286. Freitag Apr. 22, 1941 t Ayers Oct. 24, 1944

